This Program Project Grant (PPG) is designed to explore the causal pathway from pet exposure to bacteria in the home and infant gastrointestinal tract, to immune development, to pediatric allergic asthma. The Biostatistics and Data Management Core (Core B) is critical to support the development and conduct of the four Projects in this PPG. Specifically, this Core will ensure the timely and accurate acquisition of data and its dispersion to the various Projects. The Core will provide a centralized database comprised of data collected for all Projects and Cores. A centralized database is an advantage when dealing with multiple sites, assuring the accurate linkage and confidentiality of all data types, along with ease of reporting on study progress. In addition, automated reports will be generated to enable the strict and regular monitoring of data activities by the PPG investigators. All data will undergo rigorous and regular data quality review. Further, secure and automated data transfer protocols will be developed and disseminated when necessary and where needed. This Core will also provide the resources to provide all investigators with data analyses needed to address their Specific Aims. The biostatistical expertise will ensure that all four Projects are efficiently and rigorously designed, conducted, monitored, and analyzed. The biostatisticians have a long history of collaboration with each other and with the investigators, resulting in funded grants and numerous publications. The Core will provide statistical methodological development and expertise to provide up-to-date statistical methods to design and analyze the various studies in the PPG. Biostatisticians will work regularly and directly with all investigators in the preparation of manuscripts and abstracts, ensuring rigorous analysis and interpretation of study data.